In aerospace applications, it is typical to use wire harnesses as interconnects in electrical systems. However, these harnesses are often bulky, heavy, costly to build and maintain, and subject to corrosion and other defects. Further, with the advent of modular ducted fan unmanned aerial vehicles (UAVs), the ducted wing is comprised of multiple pods that require a system allowing for quick disconnect and replacement of pods around the circumference of a core vehicle. Particularly with respect to micro-air vehicle UAVs, the wire harness configuration and resultant connectors are cumbersome and weigh too much when placed around the circumference of the duct to connect to each pod. These wire harnesses do not provide structural integrity to the UAV and additional material must be used to thicken walls and bulkheads, for example, to provide such support. This additional material necessarily adds more weight to the UAV assembly. In addition, the wire harnesses are frequently modified at a significant cost to accommodate changes in these various pods.
Printed circuit boards (PCBs), on the other hand are rugged, inexpensive, and highly reliable. PCBs provide both the physical structure for mounting and holding electronic components as well as the electrical interconnection between components. A PCB consists of a non-conducting substrate, known as prepreg, upon which a conductive pattern or circuitry is formed. The most common type of prepreg is fiberglass with epoxy resin. Prepreg is available in different styles with varying amounts of resin and glass fibers, which allows the manufacturer to control the thickness between the layers and to provide the appropriate amount of resin flow between circuitry. Copper is the most prevalent conductor, although nickel, silver, tin, tin-lead, and gold may also be used as etch resists or top-level metal. Multilayer PCBs consist of alternating layers of conductor and insulating material bonded together. The conductive layers are connected by plated through-holes, which are also used to mount and electrically connect components. PCBs may be either rigid, flexible, or a combination of the two known as a rigid-flex.